The madman who tried to assassinate then-Arizona Rep. Gabrielle Giffords and wound up killing six others at a congressional event in Arizona will spend the rest of his life in jail after reportedly agreeing to plead guilty.

Jared Lee Loughner will admit to the mass shooting, which also wounded 12, in Tucson federal court Tuesday, the Los Angeles Times reports. He is expected to get a life sentence, the Associated Press said.

The expected plea comes as psychiatric experts are set to testify that Loughner was sane back in January 2011 when he opened fire, the Times reported.

While his mental capacity varies, he comprehends what he did and the charges he faces, the report added.

Many of the victims and their families are expected at the courthouse Tuesday. They will be invited to speak at a separate hearing when he is sentenced.

Loughner may still face state charges.

Giffords, who was shot in the head, still sometimes uses a wheelchair — but recently climbed the French Alps with her husband, ¬astronaut Mark Kelly.

The youngest person killed was 9-year-old Christina Taylor-Green, who was said to be interested in politics and was there to meet the congresswoman.